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//===-- FileCollector.cpp ---------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/FileCollector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.h"
using namespace lldb_private;
using namespace llvm;
static bool IsCaseSensitivePath(StringRef path) {
SmallString<256> tmp_dest = path, upper_dest, real_dest;
// Remove component traversals, links, etc.
if (!sys::fs::real_path(path, tmp_dest))
return true; // Current default value in vfs.yaml
path = tmp_dest;
// Change path to all upper case and ask for its real path, if the latter
// exists and is equal to path, it's not case sensitive. Default to case
// sensitive in the absence of real_path, since this is the YAMLVFSWriter
// default.
upper_dest = path.upper();
if (sys::fs::real_path(upper_dest, real_dest) && path.equals(real_dest))
return false;
return true;
}
FileCollector::FileCollector(const FileSpec &root, const FileSpec &overlay_root)
: m_root(root), m_overlay_root(overlay_root) {
sys::fs::create_directories(m_root.GetPath(), true);
}
bool FileCollector::GetRealPath(StringRef src_path,
SmallVectorImpl<char> &result) {
SmallString<256> real_path;
StringRef FileName = sys::path::filename(src_path);
std::string directory = sys::path::parent_path(src_path).str();
auto dir_with_symlink = m_symlink_map.find(directory);
// Use real_path to fix any symbolic link component present in a path.
// Computing the real path is expensive, cache the search through the
// parent path directory.
if (dir_with_symlink == m_symlink_map.end()) {
auto ec = sys::fs::real_path(directory, real_path);
if (ec)
return false;
m_symlink_map[directory] = real_path.str();
} else {
real_path = dir_with_symlink->second;
}
sys::path::append(real_path, FileName);
result.swap(real_path);
return true;
}
void FileCollector::AddFile(const Twine &file) {
std::lock_guard<std::mutex> lock(m_mutex);
std::string file_str = file.str();
if (MarkAsSeen(file_str))
AddFileImpl(file_str);
}
void FileCollector::AddFileImpl(StringRef src_path) {
std::string root = m_root.GetPath();
// We need an absolute src path to append to the root.
SmallString<256> absolute_src = src_path;
sys::fs::make_absolute(absolute_src);
// Canonicalize src to a native path to avoid mixed separator styles.
sys::path::native(absolute_src);
// Remove redundant leading "./" pieces and consecutive separators.
absolute_src = sys::path::remove_leading_dotslash(absolute_src);
// Canonicalize the source path by removing "..", "." components.
SmallString<256> virtual_path = absolute_src;
sys::path::remove_dots(virtual_path, /*remove_dot_dot=*/true);
// If a ".." component is present after a symlink component, remove_dots may
// lead to the wrong real destination path. Let the source be canonicalized
// like that but make sure we always use the real path for the destination.
SmallString<256> copy_from;
if (!GetRealPath(absolute_src, copy_from))
copy_from = virtual_path;
SmallString<256> dst_path = StringRef(root);
sys::path::append(dst_path, sys::path::relative_path(copy_from));
// Always map a canonical src path to its real path into the YAML, by doing
// this we map different virtual src paths to the same entry in the VFS
// overlay, which is a way to emulate symlink inside the VFS; this is also
// needed for correctness, not doing that can lead to module redefinition
// errors.
AddFileToMapping(virtual_path, dst_path);
}
/// Set the access and modification time for the given file from the given
/// status object.
static std::error_code
CopyAccessAndModificationTime(StringRef filename,
const sys::fs::file_status &stat) {
int fd;
if (auto ec =
sys::fs::openFileForWrite(filename, fd, sys::fs::CD_OpenExisting))
return ec;
if (auto ec = sys::fs::setLastAccessAndModificationTime(
fd, stat.getLastAccessedTime(), stat.getLastModificationTime()))
return ec;
if (auto ec = sys::Process::SafelyCloseFileDescriptor(fd))
return ec;
return {};
}
std::error_code FileCollector::CopyFiles(bool stop_on_error) {
for (auto &entry : m_vfs_writer.getMappings()) {
// Create directory tree.
if (std::error_code ec =
sys::fs::create_directories(sys::path::parent_path(entry.RPath),
/*IgnoreExisting=*/true)) {
if (stop_on_error)
return ec;
}
// Copy file over.
if (std::error_code ec = sys::fs::copy_file(entry.VPath, entry.RPath)) {
if (stop_on_error)
return ec;
}
// Copy over permissions.
if (auto perms = sys::fs::getPermissions(entry.VPath)) {
if (std::error_code ec = sys::fs::setPermissions(entry.RPath, *perms)) {
if (stop_on_error)
return ec;
}
}
// Copy over modification time.
sys::fs::file_status stat;
if (std::error_code ec = sys::fs::status(entry.VPath, stat)) {
if (stop_on_error)
return ec;
continue;
}
CopyAccessAndModificationTime(entry.RPath, stat);
}
return {};
}
std::error_code FileCollector::WriteMapping(const FileSpec &mapping_file) {
std::lock_guard<std::mutex> lock(m_mutex);
std::string root = m_overlay_root.GetPath();
m_vfs_writer.setOverlayDir(root);
m_vfs_writer.setCaseSensitivity(IsCaseSensitivePath(root));
m_vfs_writer.setUseExternalNames(false);
std::error_code ec;
raw_fd_ostream os(mapping_file.GetPath(), ec, sys::fs::F_Text);
if (ec)
return ec;
m_vfs_writer.write(os);
return {};
}
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